1. Field of the Invention
The present invention relates to a device for preventing burn-in of a display screen of an image display device, and to a burn-in prevention method.
2. Description of the Related Art
When a display device, such as a cathode ray tube or plasma display panel, displays images by utilizing the luminous phenomenon that accompanies the excitation of phosphor, and continuously displays a still image for a long period, so-called ‘burn-in’ results when the phosphor deteriorates. One way of preventing the burn-in of the screen is displaying an image by inverting the contrast of the luminance represented by an image signal, as disclosed in Japanese Patent Kokai (Laid Open Publication) No. H8-248935.
However, as the phosphor ages, it becomes difficult to prevent the burn-in by simply displaying an image with the inversion of the luminance contrast.